Climate and Coastal Systems

Coastal areas are where much of our population and critical infrastructure are located. Coastal lowlands in the Wet Tropics region support important agriculture and the coast is a major focus of tourism in the region.

But coastal areas are also particularly vulnerable to the impacts of climate change.

Scientists from James Cook University and CSIRO have worked with NRM groups to carefully consider the likely impacts of climate change on the resilience of coastal systems. Studies have also looked at the impact on settlements, industry and natural ecosystems, together with potential actions to enable adaptation to these changes.

Climate change and coastal systems in the Wet Tropics region

The impact of climate change on coastal systems is not independent from the impact on water, biodiversity, biosecurity and industry. In fact, it is within the coastal system of the Wet Tropics where the impacts are combined and are potentially the most devastating. This is simply due to the location of our coastal zone as climate change presents substantial risks through rising sea levels and extreme weather events such as cyclones.

Low-lying areas and islands are the most susceptible to climate change impacts in the near future in the Wet Tropics region. Critical services and infrastructure such as hospitals, the Bruce Highway, air and sea ports and rail networks are also highly vulnerable to climate change impacts simply due to their location.

Infrastructure

Rising sea levels will inundate low-lying coastal communities, as well as critical infrastructure. Some areas will be permanently submerged, while others will be flooded by sea water during storm tides. Rising sea levels will also cause increased erosion of beaches and the loss of protective coastal vegetation.

The Cairns Regional Council has commissioned analysis of the areas vulnerable to sea level rise, to help them plan for future conditions.

Ecosystems

Higher sea levels will also cause the loss of important mangrove and coastal wetland systems, sea grass beds and coral reefs, impacting on commercial fisheries and areas of traditional hunting; the conservation of the ecosystems in general will be hugely impacted.

Agricultural land

Sea level rise will cause saline intrusion, which increases the salinity of coastal waterways, wetlands and ground water (aquifers), causing major implications for vegetation, fisheries and water supply.

Agriculture on coastal floodplains will also be affected by increased salinity of rivers and salt water intrusion into groundwater.

As coastal areas tend to be low-lying, they are susceptible to flooding during heavy rainfall and this is compounded by rising sea levels, especially when combined with storm surges.

Pulses of fresh water and associated nutrient, soil and chemical runoff which enters into marine systems during floods will affect coral and other marine life in coastal and near-shore areas.

Increased disturbance from extreme events such as floods and cyclones is likely to lead to increased invasion and spread of problematic weeds and feral animals. A likely flow-on effect of this will be a decrease in the protection provided to coastal settlements by natural vegetation.

What can be done to adapt to climate change impacts on coastal systems?

As well as considering the likely impacts of climate change on coastal systems, scientists from James Cook University and CSIRO have considered the potential actions we can take to adapt to these changes. Key message include:

Use up-to-date information about the changing risks in coastal areas, especially those areas likely to experience sea level rise and flooding, for planning and development decisions.

Develop and improve ways to protect and restore coral reefs and coastal dune systems and create ways to help coastal ecosystems like mangroves to establish further inland.

Plan for an increased need for recovery work following extreme events.

For more information

A risk management tool for coastal areas is in development through the National Climate Change Adaptation Research Facility (NCCARF). A substantial number of the reports produced through NCCARF address issues associated with coastal systems, especially in the Settlements and Infrastructure research program. A full list of NCCARF publications is available for searching and download.

Recent CSIRO and Bureau of Meteorology work has resulted in an exciting new website (www.climatechangeinaustralia.gov.au), which has both detailed information about climate change and interactive tools available to the public.